The invention relates to motor vehicles in general, and more particularly to improvements in motor vehicles having power trains embodying automated torque transmitting systems (such as friction clutches) and/or automated variable speed transmission systems. Still more particularly, the invention relates to improvements in power trains wherein the automated system or systems is or are actuated in response to commands from a control unit (such as a microprocessor) which receives signals from monitoring means including one or more sensors.
It is already known to render the control unit operative in response to activation of the ignition system for the engine in the power train of a motor vehicle. Signal or signals from the sensor means which monitors the ignition system causes or cause the control unit to change the condition of the clutch (e.g., by way of a hydraulic, mechanical or other suitable actor) and/or to change the ratio of the transmission (e.g., by way of another actor). The arrangement can be such that the control unit becomes operative in automatic response to actuation of the ignition system in a sense to start the engine.
Motor vehicles of the above outlined character are disclosed in U.S. Pat. No. 4,892,014 granted Jan. 9, 1990 to Morell et al. for "ELECTRONIC CONTROLLER FOR AUTOMATIC TRANSMISSION". The disclosure of this patent is incorporated herein by reference. Morell et al. disclose one or more microprocessors serving to control an automatic transmission and being designed to change its or their condition from inoperative (idle) to operative (ready for use) in response to completion of the ignition circuit by an ignition key or a switch. A drawback of the patented apparatus is that, if the operator of the motor vehicle desires to carry out one or more particular (specific) operations or steps which can be carried out only while the microprocessor(s) is or are operative, it is invariably necessary to change the condition of the mcroprocessor(s) from inoperative to operative before the operator of the motor vehicle can proceed with the carrying out of the particular (specific) operations or steps. Thus, an operation which can be carried out only while the microprocessor(s) of Morell et al. is or are operative must be preceded by a manipulation of the ignition key or of a switch if the operator of the motor vehicle desires to carry out such operation while the microprocessor(s) is or are inoperative. This is often inconvenient to the operator, especially when it is necessary to carry out the particular (specific) operation or operations on short notice, i.e., either immediately or with a minimum of delay.